[Serusers] invite timer & calls to PSTN

[Jiri Kuthan]

At 03:34 AM 8/21/2004, O'Shaughnessy Evans wrote:
>Hello, all.  I have a problem I'm trying to work out:  when a stateful
>call goes out from the proxy to the PSTN, the fr_inv_timer will eventually
>trigger a failure.  The thing is, I don't want calls going outside my
>SIP proxy to have any timer associated with them.  I need it for calls
>to local users so they can fall back to voicemail, but I don't need it
>for anything else.  E.g. if one of my SIP users calls out to a PSTN
>number and, for whatever reason, wants that call to ring 300 times,
>the timer in the SIP proxy shouldn't inhibit that ability.
>
>I can get around this by using forward(), but if the SIP user is coming
>from a NAT'd device, I have to use a t_relay() instead and then I'm
>stuck with the timer running.
>
>Is there a way around this?  Thanks for your help.

a trivial workaroud is to drive the inv_fr_timer excessively high.

Other option is to enable silent timer -- i.e., SER not sending
408 and CANCEL, just trashing the transaction from memory.
This option is actually turned on by default, but is disabled
in run-time if some of many conditions occured:
- noisy_ctimer config option is explicitley turned on
- forking
- failure_route set up

-jiri